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Fertilzers & Hormones Versus Transplant Shock
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Bulletin #TP1027
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Horticultural Observations for Healthier Landscapes |
Does vitamin B1 help transplants take root?
How do Starter Fertilizers & Micro Nutients work ?
Vitamin B1
has been touted as a cure-all for transplant shock. Labels typically claim that
B1 aids rooting and growth of a wide range of plants.
◊ Auxin A published report from tests
done by The Sunset group (publisher of the Sunset Magazine) indicated some
interesting results. They used marigolds (fast growing) for the tests, because
the differences in growth show up quickly. Product labeling for application was
followed. They ran their own
tests on the effects of various B1 formulations on plant growth when compared
with fertilizers. They tested different combinations of formulations containing
B1: 1>
B1 alone; 2>
B1 plus iron, zinc, and manganese; 3>
B1 plus iron and phosphorus (0-2-0); 4>
B1 plus 3-10-3 fertilizer. 5>
For comparison, they included a 10-10-5 fertilizer and a control
plant given no treatment.
Two weeks after
planting, all the marigolds were established and had new leaves (except plants
given B1 alone, which lagged behind the rest). Four weeks after
planting, marigolds receiving 10-10-5 or B1 plus 3-10-3 began to flower. Flower
buds on the remaining plants opened a week to two weeks later. At the end of the
test, six weeks after planting, marigolds treated with 10-10-5 or 3-10-3 were
much bushier and darker green, and had more open flowers than
the others. When the tests were
repeated in the summer, results were similar. In both cases, marigolds treated
with products containing nitrogen were fuller and healthier, and bloomed
earlier than plants that didn't receive nitrogen. The control did as well as or
better than the B1 treatments without nitrogen.
Research has failed to demonstrate this. Yet, anecdotal reports strongly support improved
plant establishment. Why the disparity?
Hopefully this article can discover some answers.
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Testing Assumptions - Many consumers assume that products on the store shelf must have been tested to prove their claims. In most states fertilizers have to meet nutrient content requirements, and pesticides are rigorously tested for safety before EPA registration. For many other garden products, however, no such testing is required before sale to the public.
A good example is vitamin B1 (thiamine), often sold to "prevent transplant shock" and "stimulate new root growth" when planting trees, shrubs, roses and other plants.
A study in the 1930's provided the basis for such claims. Pea roots cut off from the plant were placed in a culture medium in the laboratory. The researchers knew that thiamine was normally found in roots, so they put thiamine in the culture medium and found that root growth did occur. Vitamin B1 is manufactured in plant leaves and sent to the roots, but if roots are cut off and placed in a petri plate, vitamin B1 stimulates growth of the roots when it saturates the culture medium.
Planting into in a soil
environment, is vastly different from a laboratory culture. More importantly, gardeners aren't in the habit of cutting off the root system when
planting.
This is not proof that B1 is harmful,
only that the marketing on this vitamin is over-zealous and possibly
misleading.
Transplant
shock is a
genuine concern. Skilled gardeners know that dealing with possible
transplant stress improves success.
So, what is wise in this situation?
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Starter Fertilizer,
if well designed will contain the proper amount of nitrogen,
phosphorous and potassium. It will also be a good source of
major & micro-nutrients. In bagged soil mixes all these are usually absent.
This is because the organic matter is what this soil mix is to provide - not
fertilizer. It's too difficult the provide a measured amount of nutrient
for a plant through the soil mix. Too easy to over or under fertilize.
Mycorrhizal
Fungi. Under natural conditions plants
live in close association with soil organisms called mycorrhizal fungi. These
fungi colonize plant roots and extend the root system into the surrounding
soil. Estimates of amounts of mycorrhizal filaments present in a cubic
inch of healthy soil are up to a mile of filaments. Fungal mats are now
known as the largest biological entities on the plant. The relationship
between plants and fungi is beneficial to both; the plant enjoys improved
nutrient and water uptake, disease resistance with superior survival and
growth, the fungi receives nutrients in the form of photosyntates and is able
to grow and survive. It is believed that fungi are responsible for the
world of plants being able to inhabit and evolve on land from their
aquatic origin.
Auxin is a plant hormone that aids in the initiation of adventitious roots.
Indole acetic acid (IAA) is the naturally occurring auxin found in plants.
IAA is involved in nearly every aspect of plant growth and
development. Some of the processes regulated by IAA
include formation of embryo in development,
induction of cell division, apical dominance, induction of rooting,
vascular tissue differentiation, fruit development,
and tropic movements such as bending toward light.
Naphthaleneacetic acid (NAA) is a chemical that is also proven to stimulate root growth. This chemical was initially discovered
as effective in various organisms: "Experiments with 1-naphthaleneacetic acid (NAA)
demonstrated that this auxin species promotes
cell division and cell elongation;
NAA stimulates cell elongation at concentrations that are
much lower than those required to stimulate cell division."
Humic acids, though not considered a hormone,
play several important roles such as:
increasing soil physical and biochemical activities
by improving structure, texture, water holding capacity (WHC),
and microbial population and increase soil nutrients availability, especially micronutrients.
(Nardi et al., 2017, 2021; Fuentes et al., 2018; Shah et al., 2018);
Assisting in the availability of soil nutrients is key towards
the root system uptaking the nutrient that are present.
The Bottom Line:
Some "root
stimulator" products contain a rooting hormone and fertilizer along with
vitamin B1. These other materials may increase rooting and growth, but
there is little scientific evidence that the vitamin B1 by itself has this benefit.
There is some discussion however, that adding B1 to the soil structure may help to
encourage microbial growth.
The Starter Fertilizer should be mixed into this bagged soil-mix
during planting, and done so according to the plant and hole size, as
well as the type of plant.
In some situations root growth stimulents may be called for.
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Some "root stimulator" products contain rooting hormones.
Growers are often able to propagate
a wide variety of herbaceous plants on-site through the help
of improved stock plant management techniques and
propagation protocols set by industry standards and
university research programs.
However, moderate and difficult-to-root plant species
can prevent producers from realizing their full potential.
Application of auxin-based, commercially available rooting
hormones may be the key to overcoming this challenge.
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Synthetic forms of auxin are available commercially
in the form of Indolebutyric acid (IBA) and
napthaleneacetic acid (NAA).
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Looking for this ingrediant in the root stimulator you choose
is likely to add to your success.
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The fertilizing nutrient "phosphorous" is well documented to be
important towards root growth.
Root stimulator products are important for transplant success.
If you use a root stimulator; make sure it contains
a rooting fungi, and rooting hormones. Also don't use the rooting
hormone instead of Starter Fertilizer, use it in addition.
If using B1 gives you a better sense of confidence, use that too.
The confidence that you have when planting is really an integral
part of the formula for success!
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